Stencil



(No Model.)

E. L. TARBOX. PEooESS 0E MOLDING TYPE WEEELS AND OTEEE GUEVEE SUEEAGES.

Patented Mar. 19, 1889.

I Mlm MIM i llNiTnD @rares arrivi OFFICE.

EUGENE L. TARBOX, OF BROOKLYN, ASSIGNOR TO THE NEV YORK STENOIL VORKS,OF NEW YORK, N. Y.

PROCESS F MOLDING TYPE-WHEELS AND OTHER CURVED SURFACES.

SPECIFICATION forming part of Letters Patent No. 399,945, dated March19, 1889.

Application led November 16, 1886. Serial No. 219,014. (No model.)

To all whom, t may concern:

Be it known that I, EUGENE L. TARBoX, of Brooklyn, in the county ofKings and State of New York, have invented a new and useful lmprovementin the Process of Manufacturing or Duplicating Type-Vheels and SimilarCurved Objects and a Novel Type-lVheel Produced Thereby; and I do herebydeclare that the following is a full and exact description thereof,

1o .reference being had to the accompanying drawings, and to the lettersof reference marked thereon, making apart of this speci fication, inwhich- Figure l is an elevation in perspective of i 5 an improvedsegmental mold adapted to facili-` tate the manufacture of a type-wheelby my improved process. The mold is represented with one-li alf of itscoverin g-plate broken away to disclose the radial segmental. divisionsbe- 2o neath it. A portion of these divisions is shown as empty, one ofthem with a retracting-plate fitted in position on its outer edge, andthe remainder as fitted each with a segmental block of type-metal whoseouter end 2 5 rests upon a retracting-plate, which is engaged by aset-screw to facilitate its withdrawal and adjustment. Fig. 2 is adiainetric section of Fig. l, showing one of the typeblocks in the moldpartly withdrawn; Fig. 3,

3o a plan, side elevation, and diametric section of a pattern type-wheelfor duplication by my improved process; and Fig. 1t, a similar plan,side elevation, and diametric section of a novel form of type-wlieelproduced in the matrix 3 5 obtained from the original pattern type-wheelshown in Fig. 3.

Similar letters indicate like parts in all the figures.

My invention relates to an improved process for manufacturing orduplicating typewheels and similar curved objects having devices thereonin relief or intaglio.

There it has been required to produce characters upon the periphery of awheel or other circular object in very deep relief it has been foundnecessary to carve or cut out the same by hand-a slow and expensiveprocess.

It has been sought to improve upon the cutting of the type by hand andto produce a 5o metallic type-bearing annulus by causing, with the aidof suitable mechanical devices, a

radial enlargement or expansion of the metal of the ring against diesfitted to encircle it; but the attempt has failed because of theimpracticability of thus expanding metal of 55 proper hardness andtemper for use as type, and because of the expense attending such aprocess of manufacture. It has also been sought to obtain the desiredend by encircling the rim of the wheel with a detached band 6o bearingthe type; but this has failed practically because of the difiiculty inunit-ing the ends of the bands upon different wheels, so that any two ofthem shall be exact duplicates.

The object of my invention is to produce in duplicate from a givenpattern type-wheels and similar circular devices having an endless orseamless face and the finish and sharpness of outline of the originaltype-wheel cut 7o by hand, together with such degree of hardness as maybe found desirable therein. I accomplish this result by the use of thenovel v means hereinafter described; and my inven- 5 tion consists informing in any suitable man- 7 5 nera series of independent radialcompartments about the curved surface of a suitable pattern-wheel, sothat said curved surface shall constitute the inner wall of the severalcells, filling said compartments with molten 8o metal or other suitablematerial which will admit of being introduced tliereinto in a iiuid orsemi-fluid condition and of hardening therein, allowing the material toharden in each compartment to form an angular segmental block thereinwhose inner face shall be a counterpart of the opposite face of thepattern, withdrawing radially in each compartment the block so formedtherein out from the face of the pattern far enough to 9o clear it,removing the pattern, returning the blocks to their first position,casting'in the recess frein which the pattern has been removed anydesired character or quality of material, which will thereupon receivein the matrix formed by the combined segmental blocks the impression ofthe original pattern, so as to be an exact duplicate thereof, and,finally, by an outward radial movement of the several blocks, releasingsaid duplicate to permit of roo its withdrawal. By placing apreviouslyformed hub or foundation-piece within the recess left vacantby the withdrawal of the.

pattern insuch manner as to 'leave a space between said foundation-pieceand the faces of the radial blocks a continuous facing may be formedthereon, which shall be a duplicate of the outer surface of the pattern.

The accompanying drawings illustrate the means which I preferably employto effectuate my process, and which are shown as used for themanufacture of duplicate type-wheels having each a central hub madeindependent of vthe type-bearing annulus, which is subsequently formedthereon and united thereto.

A in said drawings represents a suitable bed-plate, from which projectsa central pin or spindle, F. Upon this spindle is placed the completepattern type-wheel to be duplicated.

A series of thin radial partition-plates, B B, are fixed upon thebed-plate to abut at their inner ends against the periphery of thepattern-wheel and between the several type or other designs produced inrelief thereon. These partition-plates serve to constitute the sidewalls for a series of radial cells or compartments, C C, of which theperipheral surface of the pattern becomes the inner wall. Being ofuniform height, coinciding with the depth or thickness of the pattern, acoveringplate, E, placed upon the pattern to extend to the outer ends ofthese plates B B, will serve to close the cells, leaving their outerends alone open. When this covering-plate E is made fast, a suitablemetallic alloy-such as type-metal-brought to a fluid or semifluidcondition by heat, or a suitable plastic composition which shallspeedily harden, is poured into the outer end of each cell, so as tobecome molded therein and a counterpart of so much of the periphery ofthe pattern-wheel as is embraced by the inner end of the cell isproduced at its inner end. Vhen the composition thus cast in the cellshas hardened, the resulting mold-blocks K K are withdrawn radially farenough to fully disengage their inner ends from the pattern. Thismovement thereof is facilitated by means of adjusting-screws i-I H,working in the edge of the base-plate and engaging sliding plates towhich the blocks are made to attach themselves by lugs or offsets. Thepattern is then removed from its seat and the radialmold-blocks K K aremoved inward to their original positions, so that their inner ends willform a matrix the exact counterpart of the periphery of the pattern andof which the bed-plate A serves as the bottom plate. Within this matrixand upon the central spindle, F, a hub or spider, L, is placed, having arim of smaller diameter than the recess, but of equal depth or width,whereby an annular space is left between the rim and the innerperipheryof the mold. This annular space is then filled with plastic rubber orcelluloid or with a molten alloy or other suitable composition orcompound adapted to constitute the face of the nished wheel, the

top of the recess being covered and inclosed by the covering-plate E.Where rubber or celluloid is used for the wheel, the compound, afterbeing placed in the mold to lill 1t completely, is hardened bysubjecting the closed -mold to heat in the customary manner. If a moltenalloy be used, the mold is allowed to cool until the alloy has hardened.The radial mold-blocks K K are now again withdrawn to permit thewithdrawal of the typewheel (see Fig. 4 of the drawings) which has beenproduced, as described, in the mold.

By this process a wheel is readily produced having a metallic hub' orbody encircled by an unbroken or vsolid seamless peripheral band ofrubber or celluloid firmly united thereto and bearing type or othercharacters duplicating exactly those in the pattern-wheel.

lf preferred, the use of a previously-formed central hub or spider, L,may be dispensed with and the entire wheel (see Fig. 3 of the drawings)be formed or cast in the mold whose periphery is formed by the innerends of the radial blocks K K. In either case the periphery of themolded wheel will be an exact duplicate of the original pattern. As themold obtained as described is not injured by use, it may be employed toproduce in the manner set forth any number of duplicates of the pattern.

It is evident that my process 0f producing duplicates of a type-wheel byforming radial cells about its curved surface, casting moldblocks insaid cells, withdrawing the blocks to disengage the pattern, returningthem to their original positions to form a matrix, and, finally, castingthe duplicate wheel in said matrix, may be applied to the reproductionof all manner of curved surfaces bearing characters or designs thereonin simple relief or intaglio.

`l claim as my inventionl. The process, substantially as described, ofmanufacturing a type-wheel or other object having a curved surfacebearing characters thereon in relief or intaglio, which consists infilling a series of radial cells formed about the curved or circularsurface of a suitable pattern with a plastic composition or molten alloyadapted to conform to the type or other characters on the surface of thepattern, allowing the composition or alloy to harden into blocks incontact with the pattern, so as to retain the impression thereof,withdrawing radially within their cells these sectional mold-blocks farenough to disengage them from the pattern, removing the pattern frombetween the blocks, moving back the radial incid-blocks to theiroriginal positions, casting the material for the finished object in thematrix or recess previously occupied by the pattern, and iinaiiy againwithdrawing the mold-blocks radially to disengage them from the casting.

2. The process, substantially as described, of manufacturing atype-wheel or other object having a curved surface bearing charac- IOOIIO

ters thereon in relief or intaglio, Which consists in filling a seriesof radial cells formed about the circular or curved surface of asuitable pattern with a plastic composition or a molten alloy adapted toconform to the type or other Characters on the said surface of thepattern, allowing the composition or alloy to harden into blocks inContact with the pattern, so as to retain the impression thereof,withdrawing radially within their cells these sectional mold-blocks farenough to disen gage them from the pattern, removingthe pattern frombetween the blocks, moving back the radial mold-blocks to their originalpositions, placing a previously-formed hub or body-piece of smallerdiameter than the pattern cent-rally in the recess encircled by theradial mold- EUGENE L. TARBOX.

Witnesses:

S. A. STAVERS, S. M. MADDEN.

